LESS Compilation: Fix error parser

Error messages from native LESS
compilation are currently completely
broken; this fixes them.
Merge pull request #229 from am11/master

Corrected a variable name
Fixed source map issue with IE
Enable Browser Link menu by default
Merge pull request #230 from SLaks/less-errors

LESS Compilation: Fix error parser
Strengthened ZenCoding command
Merge branch 'master' of https://github.com/madskristensen/WebEssentials2013
Changed SurroundWith to use <div>
Enforced use of safe command execution
add whitelist to BootstrapClassValidator
Merge pull request #235 from duncanbrown/FixBootstrapClassValidatorFalsePositives

Fix erroneous Boostrap class warning
- Changed the MarginBase.UseCompiledFolder property to a string (including sub-classes: CoffeeScriptMargin.cs and LessMargin.cs)
- Updated MarginBase.GetCompiledFileName(string, string, bool) to GetCompiledFileName(string, string, string).
- If GetCompiledFileName() gets a null or empty string for the customFolder (now a string instead of a boolean) it will work as if false was passed into the old method. if it is non-null and non-empty, it will assume it is part of the path..
  - If customFolder starts with `~/` or `/` it assumes the project root, otherwise assumes it is relative.
  - In order for GetCompiledFileName() to find the project's root it looks up to each parent directory (starting with the file's directory) for the bin folder.
  - This will always assume the project's root directory is the same as the first bin directory found upward from the file being compiled!
- Updated the settings UI text to, "Compiles each LESS file into a custom folder. Prefix your output directory with a `/` to indicate that it starts at the project's root directory. Otherwise a relative path is assumed. Leave empty to effectively disable this option."
Merge pull request #236 from kodybrown/master

Allow developer to specify output location for css / coffeescript files.
Fixed #240
Fixed Html.Core reference